diff --git a/src/cargo/util/context/mod.rs b/src/cargo/util/context/mod.rs
index 54fbe50b783..c90549bf371 100644
--- a/src/cargo/util/context/mod.rs
+++ b/src/cargo/util/context/mod.rs
@@ -2155,10 +2155,7 @@ impl ConfigValue {
                     .collect::<CargoResult<_>>()?,
                 def,
             )),
-            v => bail!(
-                "found TOML configuration value of unknown type `{}`",
-                v.type_str()
-            ),
+            v => bail!("unsupported TOML configuration type `{}`", v.type_str()),
         }
     }
 
diff --git a/tests/testsuite/bad_config.rs b/tests/testsuite/bad_config.rs
index ffff3a83e77..eea8cc82307 100644
--- a/tests/testsuite/bad_config.rs
+++ b/tests/testsuite/bad_config.rs
@@ -50,7 +50,7 @@ Caused by:
   failed to parse config at `http.proxy`
 
 Caused by:
-  found TOML configuration value of unknown type `float`
+  unsupported TOML configuration type `float`
 
 "#]])
         .run();
@@ -80,7 +80,7 @@ Caused by:
   failed to parse config at `http.proxy`
 
 Caused by:
-  found TOML configuration value of unknown type `datetime`
+  unsupported TOML configuration type `datetime`
 
 "#]])
         .run();
diff --git a/tests/testsuite/config_cli.rs b/tests/testsuite/config_cli.rs
index c2978e892f0..42b44770490 100644
--- a/tests/testsuite/config_cli.rs
+++ b/tests/testsuite/config_cli.rs
@@ -502,7 +502,7 @@ Caused by:
   failed to parse config at `a`
 
 Caused by:
-  found TOML configuration value of unknown type `datetime`
+  unsupported TOML configuration type `datetime`
 "#]],
     );
 }